Boiler system



B. SCHROEDER ET AL BOILER SYSTEM June 19, 1928. 1,674,024

Filed Feb. 9, 1923 2 Sheets-Sheet l INVENTORS 6d ATTORNEY June 19, 1928.1,674,024

B. SCHROEDER ET AL BOILER SYSTEM Filed Feb. 9, 192.5 2 Sheets-Sheet 2INVEN 0R -41 ATTORNEYS Patented June 19, 1928.

.UNITED STATES PATENT OFFICE.

IBERNHARD sonnonnna, or CHICAGO, ILLINOIS, Ann CHARLES U. sAvoYn, or

HACKENS ACK, NEW JERSEY, ASSIGNORS TO THE BABCOCKKF. WILCOXCOMPANY, OFBAYONNE, NEW JERSEY, A CORPQRA'IIQI-I OF NEW JERSEY.

BOILER sYs'rEM;

Application filed February 9, 1923. Serial No. 617,997. I

The present invention relates to boiler systems in which it is desirableto remove air and gases from the boiler water to prevent corrosion ofthe metal parts of the boiler 5 system.

The invention will be best understood from the following description andthe annexed drawings, in which Fig. 1 is an elevation, partly insection, of an apparatus 10 embodying our invention, Fig. 2 is a sectionon the line 22 thereof, looking in the di rection of the arrows, andFig. 3 is a diagrammatic view illustrating the closed circuit to whichthe surge tank is connected.

Like reference characters indicate like parts in the different views.

Boiler systems, particularly those having economizers which are liableto corrosion from the oxygen in the feed water, preferably should beoperated on what is substantially a closed cycle; that is to say, thesteam, after passing through the prime movers, should be condensed andthe condensate pumped back into the boilers without expo sure to theatmosphere. It will be obvious that in such a system, the water whenonce freed of air would not be recharged with air, so long asthe systemcontinued to opcrate. losses which must be made up and a supply ofmake-up water is provided to this end, and

this make-up water necessarily carries into the system the air or gaseswith which it is charged and these gases are liable to corrode theeconomizers.

It is also found in practice that the demands of the feed pumps which,in turn, are controlled by the water levels in the boilers, are notconstant, due to variations in the op erations of the plant. so that attimesthe supply of condensate is greater than the water which is to bepumped into the boilers, and at other times is insufficient to supplythe demands of the pump. Here again, if the excess water is exposed tothe atmosphere, oxygen and other gases will be absorbed, so that whenthis excess is again fed to the economizer and boilers, the gases willbe again carried into the system.

In Figs. 1 and 2 is illustrated an arrangement for'obviating thesedifiiculties, such device being used in connection with a systemoperating on a closed cycle and with a make-up water supply and alsowith pro- In practice, however, there are water vision for taking'careof excess condensate or for supplying the necessary make-up water in theevent that the condensate is'insufiicient to meet the demands of theboilers.

In the arrangement illustrated in Fig. 1, the pipe 10 is the carrier ofthe condensate from the condensers to the feed pumps, the water flowingdown through the pipe'10 and out of the pipe 11 to the feed pumps. A

T 12 in the pipe 10 communicates through a pipe 13 with a tank 14 whichis opened to the atmosphere through a pipe 15at-its top.

The pipe 13 enters the tank 14 well toward the bottom of the tank. Atthe upper part of the tank is a make-up water inlet 16 havmg afloat-controlled valve 17 which delivers water to a distributing pan 18.An overflow pipe 19 is connected to the tank 14, so that when the tankbecomes too full, the surplus water will flow over the plate 20 and outof the pipe 19 to any proper storage receptacle.

A steam pipe 21 supplies steam to a series of perforated pipes 22 in thebottom of the tank 14. The steam flow through the pipe 21 is controlledby a regulating valve 23 controlled, in turn, by a thermostat 24 whichmay. have an expansible fluid by which the changes in pressure therein,due to changes of temperature in the water in the tank. 14, will betransmitted through the pipe 25 to the valve 23 to control the supply ofsteam through the pipe 21.

Referring now to Fig. 3 in which we have boiler, the steam and waterdrum of which is connected by a pipe 27 to a turbine 28, the exhaustfrom which is conducted to a condenser 29. The condensate from thecondenser is forced by a pump 30, through the pipe 10, 11, and a pump 31forces the water through a pipe 32 and the high pressure stage 33 of aneconoinizer back to the boiler. A low pressure 6001101111291 34: isalsoillustrated connected by pipes'35 and 36 to the pipe 10, on oppositesides ofa valve 37 there in, the pipes 35 and 36 preferably being provided with valves 38 and 39. By closing the valves 38 and 39 and openingthe valve 37, the low pressureeconomizer is disconnected from thesystem. By opening thevalves 38 and 39 and closing the valve 37, thewater is forced by the pump 30 through the low pressure economizer.

illustrated the closed circuit,26 is a steam- In operation, the tank 14will serve to receive any difl'e're'i'ices in the water flowing throughthe pipes 10 and 11 or will supply water to make up such differences.For instance. it the condensate flowing into the pipe 10 is greater inamount than that required from the pipe 11. the water will back up intothe tank 1d, any excess passing over the plate 20 and out of theoverflow pipe 19. Similarly, if the supply of the pipe 10 isinsullicient to provide enough water through the pipe 11 in accordancewith the demands of the boiler, this difference is made up through thepipe 13. In other words, the pipe 13 and the tank 14 will take care ofthe surges in the water supply system.

ll", in operation, the water stored in the tank 14 is drawn on so thatits level falls below a predetermined point, then the float valve 17will he opened and the make-up water will flow from the pipe 16 untilthe level in the tank H is restored. It is this make'up waterparticularly which would carry air into the system. and we thereforeprovide the pipes 22 by which live steam may be passed into the water inthe tank 14 to raise its temperature preferably to a point near theboiling point so as to drive elf the air and gases through the outlet15. The quantity of 'ater in the ta'k let is, of course. comparativelysmall. so that the amount of heat required to raise this small quantityof water will be almost negligible, and yet such heat will be applied ata point where it will be most eliicient in removing the-air.

Even it no make-up water is to be heated to drive off the air and gasestherefrom, nevertheless it is desirable to heat the water in the. surgetank 1% to near the boiling point. so that such water will not come intocontactwith the atmosphere. The heating means raises the temperature ofthe water suliiciently to cause vapor to be driven oli through theventpipe. thereby preventing air from the atmosphere entering the surgetank.

Furthermore, since the amount of water in the tank 14 is small comparedwith the total amount of feed water passing through the pipes 10 and 11,the temperature of the feed water is raised only slightly by the smallamount of water heated in the tank 14. Consequently. the feed water issupplied to the ec'onomizer cool enough to permit. the economizer tooperate efliciently.

The; thermostat 24 will maintain the temperature of the water in thetank 14 at approximately the desired temperature which will be selectedso as to drive ofi' the desired percentage of the air and gases with theleast expenditure of heat.

It will be obvious that, by our invention, we provide means by which thesurges in the supply will be taken care of Without exposing the water tothe atmosphere, and by which any make-up water will be freed from air orgases before passing into the system and, at the same time,accomplishing this with a minimum expenditure. of heat and a minimumraisingol' the tei'iiperture of the teed water.

It will be understood that the flpplltillltil'l of our invention may bewidely varied. The heat may be supplied to the water in the tank 14 inany other desired manner, though we find that the direct condensation oflive steam in the water is ellicient for our purpose.

id e claim:

1. In a boiler plant system having a closed circuit including a.condenser and boiler feed pump. a surge tank outside the said circuitbut connected thereto between the said condenser and said feed pump toreceive and supply condensate from and to the system to compensate fortemporary increases and decreases of the supply of condensate ascompared with the demands of the pump, a make-up water connection intothe tank, means to regulate the flow of ma ke-up water into the tank inaccordance with the level oi the water therein, and means for removin;gases from the water in said tank.

2. In a boiler plant system having a closed circuit including acondenser and boiler teed pump, a surge tank outside the said circuitbut connected thereto between the said condenser and said 'l'eed pump toreceive and supply condensate from and to the system to compensate fortemporary incre: res and decreases of the supply of condensate ascompared with the demands of the pump, the connection between the systemand the tank being" below the normal water level in the tank, a make-upwater connection into the tank. means to regulate the flow of make-upwater into the tank in accordance with the level of the water therein.and means for removin gases from the water in said tank.

3. In a boiler plant system havinga closed circuit including a condenserand boiler teed pump, a surge tank open to the atmosphere and outsidethe said circuit but connected thereto between the said condenser andsaid teed pump to receive and supply condensate from and to the systemto compensate for temporary increases and decreases of the supply ofcondensate as compared with the demands of the pump, a make-up waterconnection into the tank. means to regulate the flow of make-up waterinto the tank in accordance with the level of the water therein, andmeans to heat the water in the tank to remove air and gases therefrom.

at. In a boiler plant system having a closed circuit including; acondenser and boiler feed pump, a surge tank open to the atmosphere andoutside the said circuit but connected thereto between the saidcondenser and said t'eed pump to receive and supply condensate from andto the system to compensate for temporary increases and decreases of thesupply of condensate as compared with the demands of the pump, a make-upwater connection into the tank, means to regulate the flow of make-upwater into the tank in accordance with the level of the water therein,and means to heat the water in the tank to a predetermined temperatureto remove air and gases therefrom.

5. In a boiler plant system having a'closed circuit including acondenser and boiler feed pump, a surge tank open to the atmosphere andoutside the said circuit but connected thereto between the saidcondenser and said feed pump to receive and supply condensate from andto the system to compensate for temporary increases and decreases of thesupply of condensate as compared with the demands of the pump, a make-upwater connection into the tank, means to regulate the flow of make-upwater into the tank in accordance with the level of the water therein,means to pass live steam into the Water in the tank to heat it to removeair and gases therefrom and a thermostat in the water to control theflow of live steam to maintain the water at a predetermined temperature.

6. In a boiler plant system having a closed circuit including acondenser and boiler ieed pump, a surge tank. open to the atmosphere andoutside the said circuit but connected thereto between the saidcondenser and said feed pump to receive and supply condensate from andto the system to compensate for temporary increases and decreases of thesupply of condensate as compared with the demands of the pump, and meansto heat the water in the tank to prevent the absorption of air and gasesby the Water in the tank. 7 7. In a boiler plant system havinga closed Icircuit including a condenser and boiler feed feed pump to receive andsupply condensate from and to the system to compensate for temporaryincreases and decreases of the supply of condensate as compared with thedemands of the pump, and means to heat the water in the tank to apredetermined temperature and to maintain it at such temperature toprevent the absorption of air and gases by thewater in the tank.

8. In a boiler plant system having a closed circuit including acondenser and boiler feed pump, a surge tank of relatively small sizecompared to .the volume of the feed water and open to the atmosphere,said surge tank being located outside the said circuit but connectedthereto whereby said tank is adapted to receive and supply condensatefrom and to the system to compensate for temporary increases anddecreases of the supply of condensate as compared with the demands ofthe pump, said connection being at the lower part of the tank, a make-upWater connection into the tank, means to regulate the How of make-upwater into the tank in accordance with the level of the water therein,and means to heat the Water in the tank to a predetermined temperatureand to maintain it at such temperature to drive off the air and gasesfrom the water and to prevent the absorption of air and gases by thewater in the tank.

In a boiler plant system having a closed circuitincluding a condenserand boiler feed pump, a surge tank outslde the said circuit butconnected thereto between the said condenser and said feed pump toreceive and supply condensate from and to the system to compensate fortemporary increases and decreases of the supply of condensate ascompared with the demands of the pump, a make-up water connection intothe tank, means to regulate the flow of makeup water into the tankinaccordance With the level of the water therein, and means for preventingthe absorption of air in the water in said surge tank.

BERNHARD SCHROEDER. CHARLES U. SAVOYE.

